Tea fact file
- 3.5 million ha grown worldwide, mainly in Asia
- 133%: increase in area harvested in Vietnam, one of the top five producing countries, since 1995
- 3 main varieties: Assam, China, Cambodian
Tea is one of the leading crops in the move towards a more sustainable agriculture.
The major environmental issues in growing tea include:
- Loss of habitats and effects on biodiversity
- Soil erosion on the often hilly terrain
- Water pollution and reduction in soil health by agrochemicals
Paraquat can be used to maintain a managed, non-competitive weed flora which provides habitats to encourage biodiversity and helps prevent soil erosion. Paraquat does not affect soil health and does not pollute soil or surface waters.
Paraquat only removes the top growth of well-established weeds and does not affect the germination of new seedlings. This maintains the balance of the weed flora and prevents shifts to noxious species simply because bare ground is less available for them to colonize. The presence of non-competitive vegetative cover helps to stabilise the soil, resisting erosion, and also provides habitats to encourage biodiversity. The wildlife encouraged will include predators of insect pests, which would otherwise have to be controlled chemically.
Paraquat’s unique combination of biological and physico-chemical properties, particularly its non-systemic action and extremely strong soil adsorption, give it a very robust environmental profile. When paraquat makes contact with soil, it is immediately very tightly bound to soil particles, making it both immobile and inactive. Paraquat can be safely sprayed between the crop rows without fear of damaging the tea plants. It cannot move to the roots and up into the shoots. Bark cannot be penetrated by paraquat meaning that it can be sprayed right up to the base of the bushes.
Paraquat cannot leach into water being so tightly bound to soil. Used as recommended, paraquat is not hazardous to fish or invertebrates because, besides its immobility, even if paraquat spray should drift onto ponds, rivers or ditchwater, it is rapidly removed by adsorption to plants and sediments, and by microbial degradation.